Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2006: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 2005: ¥1,700,000 (Direct Cost: ¥1,700,000)
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Research Abstract |
Recently, the technology behind ultra-short laser pulse generation, based on stimulated Raman scattering, has been receiving a special interest. However, the total number of spectral line generated so far was smaller than the theoretical prediction. This behavior was explained by the laser bean diffraction caused by the intensity dependent Raman conversion. In order to suppress the diffraction effect and increase the number of Raman spectral lines, where these spectral lines have similar intensities, a hollow core fiber was employed. This fiber is the interaction region of the scheme, the high-frequency bi-harmonic excitation of small Stokes shift media. The main of this work was to increase the number of spectral lines, where the intensity of each spectral line is the same, and remove the diffraction effect. Broad Raman-multi-frequency spectra were generated from the resonant two-color excitation of the deuterium molecule rotational Raman transition (J=0>2), using ultraviolet bi-harmonic lasers with a quartz hollow fiber. Fifty pure rotational Raman spectral lines (34 lines that have intensity within 10% of the strongest spectral line) from 230 to 290 nm were generated. This number of Raman spectral lines was agreed with theoretical prediction.
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